Pneumonia, TB, COPD Flashcards
(27 cards)
what are the symptoms of pneumonia?
typical: pleuritic chest pain, SOB, fever, cough (productive, likely rusty/green sputum)
atypical (headache, myalgia, arthralgia)
what are the signs of pneumonia?
fever, consolidation, pleural effusion (dullness to percussion)
if pneumonia is suspected what tests should be done?
Chest X-ray, FBC, pulse oximetry (to see o2 sats)
+ microbiology investigations: i.e: sputum, blood culture, serology
What is the most common pathogen to cause pneumonia and describe it?
streptococcus pneumoniae
alpha (greening) hemolytic strep, that is optochin sensitive
apart from strep pneumoniae, what organisms can also cause pneumonia?
Heamophilus influenzae Influenza A (virus) mycoplasma pneumonia legionella pneumophilia chlamydia pneumonia
what are the atypical pneumonia pathogens and why can they be difficult to identify?
chlamydia pneumonia
mycoplasma pneumonia
legionella pneumophilia
coxiella
difficult as cannot be grown on cultures, relies on serology and antigen tests
describe how you might identify legionella infection?
during the first 2 weeks of the resp infection, legionella antigen is detectable in the urine- can do ELISA test (antigen stick to antibody)
but after two weeks antigen will be too weak in the urine.
what is it in TB which gives it its waxy cell wall and what is the benefit of this?
mycolic acid
significant virulence factor: resists complement deposition, phagocytosis, lysozyme, and oxygen radicals
TB is what kind of bacteria and therefore to be identified needs what?
alochol and acid-fast (AAFB)
won’t stain with gram stain
therefore needs
zeihl nelson stain (ZN)
+ AP stain - auramine phenol: flurescence microscope (faster + sensitive)
+ LJ slope - lowestein jensen slope: special multure medium, speeds up growth of TB
OR MGIT- mycobacterium growth indicator tube
OR PCR- Xpert
apart from sputum, blood cultures or urine, what else might you take to identify a respiratory infection?
BAL- bronchoalveolar lavage
What organism causes pulmonary tuberculosis?
mycobacterium tuberculosis or mycobacterium bovis
Describe what happens in TB infection?
TB gets into lungs
forms local granuloma
Most TB is killed, few survive and evade host defence (due to waxy layer can live in macrophage)
px is normally asympomatic/mild symptoms
(or can get disease in immunocomp)
TB lies dormant until reactivated when the host immune system wanes.
causes caseation, cavitation and fibrosis
Investigations for suspected TB
CXR
Sputum/BAL for culture
Tissue Biopsy - histology
bloods (FBC, ESR etc)
Known COPD patient gets increased sputum, cough and SOB. What do you think it is/next steps?
exacerbation caused by infection - likely by organism which has already colonised them
either viral: rhino, corona viruses, para/influenza
or bacterial: strep. pneumo, hemophilus influenza
take sputum + culture
treat with relevant abx, based on predominant organism grown
what is bronchiecstasis? and what can cause it?
irreversible, abnormal dilatation of the bronchi, which chronic inflammatory and fibrotic changes and excess mucus secretions
severe bacterial infection: whooping cough/TB
What are the symptoms of bronchiecstatis?
chronic cough, lots of sputum production, haemoptyesis, generally ill
known bronchiescstatis px has exacerbation- what do you do/what do you think it is?
infection - caused by already colonising organisms
likely strep pneumo, h. influenza
take sputum culture and treat based on predominant organism grown
what is cystic fibrosis? & what is the consequence?
autosomal recessive disease, abnormality of CFTR gene, means cl- transporter doesn’t work, therefore, secretions are much thicker and can plug off lumens.
effects many organs, i.e. exocrine, but also lungs.
Viscous secretions plug the airways and causes bronchiecstasis and increased likelihood of resp infection
what organisms likely cause resp infection in those with CF? what do you do to test?
changes with age!
infants- staph aur.
children- hemophilus influenza
adults- pseudomonas
sputum culture
first line antibiotic treatment for a pneumonia caused by strep pneumonia infection?
amoxicillin
if the pneumonia is caused by one of the aypical pathogens (chlamydia, legionella, coxiella, mycoplasma) what antibiotics would you used instead?
reistant to amoxicillin therefore
any of:
macrolides (clarithryomycin!, erythromycin)
fluroquinolones (ciprofloxacin, levofloxacin)
tetracyclines (doxycycline)
someone with TB has a lymph nodes biopsy- what might be seen?
caseating granuloma
HIV positive has a non-productive cough and breathlessness on exertion- what organism might be causing this?
pneumocystis jiroveci
If the px have a non productive cough but you want to culture a sample, what would you do?
induced sputum: hypertonic saline to increase secretions- will make them caught sputum
or BAL- bronchoalveolar lavage
